1. Field of the Invention
The present invention relates to a method of and an apparatus for removing and replacing a weft yarn when it is broken in the yarn inserter in a jet loom.
2. Description of the Prior Art
The replacement of broken weft yarns in jet looms is disclosed in Japanese Patent Publication Nos. 45-26590 and 46-25543. In each of the disclosed arrangements, the end of a weft yarn is drawn by an air stream to a prescribed position, but the weft yarn is not automatically guided but instead is manually guided. More specifically, when the weft yarn is broken during a weaving process, the end of the weft yarn is required to be manually drawn from a yarn supply to the open end of a guide tube or the like. At the time the weft yarn is cut off between the yarn supply and a main nozzle during a weaving process, the weft yarn has to be manually wound as by a rotating yarn guide in as many turns as required around the storage drum in a weft storage device. In view of the above conventional practice, there have been demands for automatic weft threading arrangements and automatic auxiliary weft winding arrangements.
Japanese Laid-Open Patent Publication No. 53-38749 reveals a device for threading a metered weft yarn through a weft inserting nozzle. The weft yarn threading device operates by first storing the metered weft yarn as loops on an air stream in a storage tube and then guiding the weft yarn to the weft inserting nozzle. Therefore, the disclosed weft yarn threading device could not be incorporated in a drum-type weft storage device.
Drum-type weft storage devices have widely been employed in the art. There have also been demands in the art for a method of and an apparatus for automatically threading a weft yarn in the drum-type weft storage devices.